Stabilizer for road-grading machines



g- 1930- J. L. BECKER 1,773,254

STABILIZER FOR ROAD GRADING MACHINES Filed Dec. 7, 192 2 Sheets-Sheet 1 iNVENTOR Aug. 19, 1930. J. L. BECKER 1,773,254

STABILIZER FOR ROAD GRADING MACHINES Filed Dec. 7, I928 2 Sheets-Sheet 2 Patented Aug. 19, 1930 UNITED STATES,

. JOSEPH. L. BECKER, OF STILLWATER, MINNESOTA it STABILIZER FOR ROAD-GRADING MACHINES Application filed December 7, 1925. Serial No. 324,472.

This invention relates to road grading machines and the primary object is to provide means of a novel, efficient, and practical nature for preventing the transverse teetering or oscillations of the grader blade which occurs especially when the machine is travelling at a relatively high speed. The condition noted is not particularly noticeable in slow moving graders such as horse drawn machines that until recent years have dominated the market. But with the tractor pushed and pulled'graders rapidly coming into use, there is a corresponding demand for motor-graders that will not only displace the horse but which will operate at a considerably greater rate of speed. Motorized grading machines capable of travelling at relatively higlt speeds are now in use but it is found that they cannot be successfully operated at such speeds because of the instability of the blade and machine when travelling over the road under such conditions. Thus,

I when the machine is travelling at any speed up to about eight or ten miles anhour the blade functions, in the usual manner,'to shave off the high spots and fills in the low spots with the forwardly pushed volume of loose dirt. The reaction of the road surface to the blade presents no serious obstacles. But under hi h speed conditions the reaction of the irregular road surface results in entirely different consequences. Thus, for instance, when the left end of the grader blade successively passes over a hollow and then a high 36 spot it normally has a very decided tendency to first throw the right end of the blade up and thendown causing the latter end to dig deep into the road at a point where no removal of dirt is unnecessary. Nor does the 4 trouble cease there. It is found that as the machine continues in its rapid movement the oscillation of the blade becomes more pronounced and cannot be eliminated except by first reducing the speed to a very slow de- "gree, and the road is then left in-a worse condition than before the machine had passed over it. This teetering or oscillating of the blade, transversely'with respect to the road, can be overcome to some extent by providing a very heavy machine frame and then con- 'necting the grader blade to it with very sturdy ad uStment connections, but evenin most of such cases the wabbling or oscillation of the blade is imparted to the main frame to a degree that is sufficient to spoil the work of the blade. I i I F To overcome these objections, I provide each end of the scraper blade with a yieldingly mounted caster wheel that travels rearwardly of the blade or over the already graded road surface. The effect of these casters is such that it prevents the previously described oscillations of the blade, and consequently of the entire machine, because the casters tend to prevent the blade ends from dropping into hollows, as they would otherwise do, and also neutralizes any teetering action of the blade because of their constant contact with the blade-traversed or graded surface.

The invention is fully disclosed in the accompanying drawings, wherein:

Fig. 1 is a side elevation of the central portion of a road grading machine to which my invention is applied.

Fig. 2 is a sectional elevation of the machine as seen on the line 22 of Fig. 1.

Fig. 3 is an enlarged top or plan view of the right end of a grader blade to which my stabilizing unit has been attached.

Fig. 4 is an elevation of the device as shown in'Fig. 3.

Fig. 5 is a modification of the device as shown in Fig. 4.

Referring to the drawing more particularly .and by reference characters, A and B designate the usual laterally disposed beams of the main frame of the grader. This frame, together with the supporting wheels and motive power unit (not shown) may be of any well known or suitable construction and are therefore not illustrated in detail. The grader blade, C, is secured by brackets D to a circle E, carried by a floating frame F that is universally connected, as at G, to the machine proper, and is supported at its rear by laterally disposed adjusting devices H and J, by means of which the frame F and the blade C may be vertically and angularly adjusted with respect to the main frame A-B. The

' blade C. The bracket is provided with a air of verticall ugs and 8 in w ich a shaft 9 is slidabl and rotata-bly mounted. rearwardly and ownwardly directed fork 10 is rigidly secured to the shaft 9, between the'lugs 7 and 8, and

carries awheel 11. This wheel is preferably all which the shaft 9 may oscillate and slide and provided with a wide rubber tire, so that it will have a substantial bearing surface upon the road.

Threaded in the lug 7 is a bushing 12 in this bushing is adjustably secured, with respect to the lug, by a lock nut 13. A-partially com ressed s ring 14 is interposed between the ower end'ofthe bushing and the yoke or '7 fork 10, and this spring, the tension of which is adjustable by regulatin the bushing 12, has a tendency to constant y push the caster wheel 11- down against the ground.

As the machine moves forward with the 0 blade lowered to an operative position, the

caster wheels. 11 constantly exert a downward pressure upon the road, and while this res'sure reacts with a lifting tendency to the lade such lift is not suflicient to materially eli'ect the normal vertical or transverse angular ad'ustments that may be required to be made. nd, as the wheels are permitted to trail, in line .with the shafts 9, they will always operate smoothly upon the graded road surface immediately in the rear of the ends of the blade. When one end of the blade then passes over a depression in the road it will of course have a tendency to drop into such a depression, but this tendency is immediately counteracted by the trailing caster operating under the s ring 14, which s ring,

becoming more great y depressed, hol s the blade at substantiall the same level as it had I when passing over t e road surface which is then supporting the roller 11. If the de res- .sion is sufliciently pronounced there Wlll of course be a lowering of both the blade end and the caster, and, conversely, when an unusual high spot is met with (it being assumed that the machine is travelling at high speed) there will be a violent lifting jar to one end of the blade, but this jar will not result in a corresponding dig by the other end of the blade, nor in the oscillation of the blade or machine, as previously described, due to the fact that the dro pin caster engages the ground prior to t e b ade engagement and thus cushions the movement that would other wise result in a undesirable gash or dig in the road. In short, the two casters, mounted aligned, bearing forming in the manner set forth, always travel on the graded road surface, and functlomn under the action and reaction of the adyustable springs 14, serve to stabilize the vertlcal resistance and slack at the two ends of theblade, and by so doing give the entire machine an equilibrium and smoothness of operation that to my knowledge, have heretofore been unknown. I

1 In-the modification shown in Fig. 5v the wheel 15 is carried in a yoke or fork 16 securedto the end of a leaf spring 16, the front end of which is secured, as by clips 17, to a trunnion 18 that is rotatable on a bolt 19 carried in the bracket 20. In this structure the leaf spring is substituted for the previously described spring 14. Otherwise the operation and function of the device is substantial- 1y identical with that shown in the other views.

It is understood that suitable modifications may be made in the general design and structural details of the invention as herein shown, provided, however, that said modifications come within the spirit and scope of the ap-' pended claims. I

vHaving now therefore fully shown and described my invention, what I claim to be new and desire to protect by Letters Patent isi 1. A stabilizer for a road grader, having a cutting blade comprising a pair of wheels yieldably mounted with respect to the ends of the blade and adapted to travel upon the road surface traversed b the blade.

2. A grader blade sta ilizer comprising means gieldably mountednear the ends of the bla e for engagement with the road surface traversed by the said blade ends.

3. A grader blade stabilizer comprising means gieldably mounted near the ends of the bla e for engagement with the road surface traversed by the said blade ends, said means including a pair of normally spring depressed caster wheels.

4. A stabilizing attachment for a grader blad6,-COII11'1S1D a pair of wheels, one at each end 0 the lads, and means for yield mglg' depressing the the lade.

- 5. A stabilizing attachment for a. grader blade,compris1ng a pair of wheels and means for yieldingly mountin the wheels to the respective ends of the ilade so as to permit them to trail therebehind.

6. A stabilizing attachment for a grader blade, comprising a pair of brackets secured to the ends of the blade, anda pair of yieldably depressed casters carried-by said brackets.

blade, comprising a pair ofbrackets, secured to the ends of the blade, a pair of wheels carried by the brackets, and. adjustable means for yieldin l depressin the wheels.

; 8 A sta attac cut for a grader wheels with respect to 7. A stabilizing attachment for a grader izo slidably and rotatably secured near the ends v wheels secured to the of the blade, trailin evices normally pressshafts, and spring ing the shafts and wheels downwardly. a

9. A stabilizing attachment for a grader blade, comprising a trailing wheel and means for mounting the wheel to one end of the blade so that it may trail therebehind, said means including a spring tending to press the roller down below the normal level of the cutting edge of the blade.

10. In a road grader, a main frame, a second frame adjustably connected to and disposed under the main frame, a grader blade carried by the second frame, and a pair of spring depressed upwardly yieldable wheels carried by the grader blade and attached so as to trail therebehind upon the road surface traversed by the blade, said wheels being mounted upon the grader independent of any connection between the two frames.

In testimony whereof I aflix my signature.

' JOSEPH L. BECKER, 

